drivers/mfd/da9052-i2c.c

   1 /*
   2  * I2C access for DA9052 PMICs.
   3  *
   4  * Copyright(c) 2011 Dialog Semiconductor Ltd.
   5  *
   6  * Author: David Dajun Chen <dchen@diasemi.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/module.h>
  17 #include <linux/input.h>
  18 #include <linux/mfd/core.h>
  19 #include <linux/i2c.h>
  20 #include <linux/err.h>
  21
  22 #include <linux/mfd/da9052/da9052.h>
  23 #include <linux/mfd/da9052/reg.h>
  24
  25 #ifdef CONFIG_OF
  26 #include <linux/of.h>
  27 #include <linux/of_device.h>
  28 #endif
  29
  30 /* I2C safe register check */
  31 static inline bool i2c_safe_reg(unsigned char reg)
  32 {
  33         switch (reg) {
  34         case DA9052_STATUS_A_REG:
  35         case DA9052_STATUS_B_REG:
  36         case DA9052_STATUS_C_REG:
  37         case DA9052_STATUS_D_REG:
  38         case DA9052_ADC_RES_L_REG:
  39         case DA9052_ADC_RES_H_REG:
  40         case DA9052_VDD_RES_REG:
  41         case DA9052_ICHG_AV_REG:
  42         case DA9052_TBAT_RES_REG:
  43         case DA9052_ADCIN4_RES_REG:
  44         case DA9052_ADCIN5_RES_REG:
  45         case DA9052_ADCIN6_RES_REG:
  46         case DA9052_TJUNC_RES_REG:
  47         case DA9052_TSI_X_MSB_REG:
  48         case DA9052_TSI_Y_MSB_REG:
  49         case DA9052_TSI_LSB_REG:
  50         case DA9052_TSI_Z_MSB_REG:
  51                 return true;
  52         default:
  53                 return false;
  54         }
  55 }
  56
  57 /*
  58  * There is an issue with DA9052 and DA9053_AA/BA/BB PMIC where the PMIC
  59  * gets lockup up or fails to respond following a system reset.
  60  * This fix is to follow any read or write with a dummy read to a safe
  61  * register.
  62  */
  63 static int da9052_i2c_fix(struct da9052 *da9052, unsigned char reg)
  64 {
  65         int val;
  66
  67         switch (da9052->chip_id) {
  68         case DA9052:
  69         case DA9053_AA:
  70         case DA9053_BA:
  71         case DA9053_BB:
  72                 /* A dummy read to a safe register address. */
  73                 if (!i2c_safe_reg(reg))
  74                         return regmap_read(da9052->regmap,
  75                                            DA9052_PARK_REGISTER,
  76                                            &val);
  77                 break;
  78         case DA9053_BC:
  79         default:
  80                 /*
  81                  * For other chips parking of I2C register
  82                  * to a safe place is not required.
  83                  */
  84                 break;
  85         }
  86
  87         return 0;
  88 }
  89
  90 /*
  91  * According to errata item 24, multiwrite mode should be avoided
  92  * in order to prevent register data corruption after power-down.
  93  */
  94 static int da9052_i2c_disable_multiwrite(struct da9052 *da9052)
  95 {
  96         int reg_val, ret;
  97
  98         ret = regmap_read(da9052->regmap, DA9052_CONTROL_B_REG, &reg_val);
  99         if (ret < 0)
 100                 return ret;
 101
 102         if (!(reg_val & DA9052_CONTROL_B_WRITEMODE)) {
 103                 reg_val |= DA9052_CONTROL_B_WRITEMODE;
 104                 ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
 105                                    reg_val);
 106                 if (ret < 0)
 107                         return ret;
 108         }
 109
 110         return 0;
 111 }
 112
 113 static const struct i2c_device_id da9052_i2c_id[] = {
 114         {"da9052", DA9052},
 115         {"da9053-aa", DA9053_AA},
 116         {"da9053-ba", DA9053_BA},
 117         {"da9053-bb", DA9053_BB},
 118         {"da9053-bc", DA9053_BC},
 119         {}
 120 };
 121
 122 #ifdef CONFIG_OF
 123 static const struct of_device_id dialog_dt_ids[] = {
 124         { .compatible = "dlg,da9052", .data = &da9052_i2c_id[0] },
 125         { .compatible = "dlg,da9053-aa", .data = &da9052_i2c_id[1] },
 126         { .compatible = "dlg,da9053-ba", .data = &da9052_i2c_id[2] },
 127         { .compatible = "dlg,da9053-bb", .data = &da9052_i2c_id[3] },
 128         { .compatible = "dlg,da9053-bc", .data = &da9052_i2c_id[4] },
 129         { /* sentinel */ }
 130 };
 131 #endif
 132
 133 static int da9052_i2c_probe(struct i2c_client *client,
 134                                        const struct i2c_device_id *id)
 135 {
 136         struct da9052 *da9052;
 137         int ret;
 138
 139         da9052 = devm_kzalloc(&client->dev, sizeof(struct da9052), GFP_KERNEL);
 140         if (!da9052)
 141                 return -ENOMEM;
 142
 143         da9052->dev = &client->dev;
 144         da9052->chip_irq = client->irq;
 145         da9052->fix_io = da9052_i2c_fix;
 146
 147         i2c_set_clientdata(client, da9052);
 148
 149         da9052->regmap = devm_regmap_init_i2c(client, &da9052_regmap_config);
 150         if (IS_ERR(da9052->regmap)) {
 151                 ret = PTR_ERR(da9052->regmap);
 152                 dev_err(&client->dev, "Failed to allocate register map: %d\n",
 153                         ret);
 154                 return ret;
 155         }
 156
 157         ret = da9052_i2c_disable_multiwrite(da9052);
 158         if (ret < 0)
 159                 return ret;
 160
 161 #ifdef CONFIG_OF
 162         if (!id) {
 163                 struct device_node *np = client->dev.of_node;
 164                 const struct of_device_id *deviceid;
 165
 166                 deviceid = of_match_node(dialog_dt_ids, np);
 167                 id = deviceid->data;
 168         }
 169 #endif
 170
 171         if (!id) {
 172                 ret = -ENODEV;
 173                 dev_err(&client->dev, "id is null.\n");
 174                 return ret;
 175         }
 176
 177         return da9052_device_init(da9052, id->driver_data);
 178 }
 179
 180 static int da9052_i2c_remove(struct i2c_client *client)
 181 {
 182         struct da9052 *da9052 = i2c_get_clientdata(client);
 183
 184         da9052_device_exit(da9052);
 185         return 0;
 186 }
 187
 188 static struct i2c_driver da9052_i2c_driver = {
 189         .probe = da9052_i2c_probe,
 190         .remove = da9052_i2c_remove,
 191         .id_table = da9052_i2c_id,
 192         .driver = {
 193                 .name = "da9052",
 194 #ifdef CONFIG_OF
 195                 .of_match_table = dialog_dt_ids,
 196 #endif
 197         },
 198 };
 199
 200 static int __init da9052_i2c_init(void)
 201 {
 202         int ret;
 203
 204         ret = i2c_add_driver(&da9052_i2c_driver);
 205         if (ret != 0) {
 206                 pr_err("DA9052 I2C registration failed %d\n", ret);
 207                 return ret;
 208         }
 209
 210         return 0;
 211 }
 212 subsys_initcall(da9052_i2c_init);
 213
 214 static void __exit da9052_i2c_exit(void)
 215 {
 216         i2c_del_driver(&da9052_i2c_driver);
 217 }
 218 module_exit(da9052_i2c_exit);
 219
 220 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 221 MODULE_DESCRIPTION("I2C driver for Dialog DA9052 PMIC");
 222 MODULE_LICENSE("GPL");